Training camp got underway for the New England Patriots last week under rainy skies, officially kicking off the 2013 campaign.

There are a number of fascinating positional battles this summer in New England, including a collection of free-agent and rookie receivers tasked with replacing Wes Welker, Brandon Lloyd and Aaron Hernandez. While Rob Gronkowski remains sidelined recovering from offseason back surgery, there are opportunities for some new tight ends to emerge as well.

Here's a collection of the best pics from the first few days of camp, along with updates on how things are coming together for Bill Belichick's latest edition.

With the total turnover at the receiver spot, the Patriots need Amendola to be a reliable threat, week in and week out. With just a handful of practices under his belt, it looks like Amendola might be on the verge of becoming a major NFL star.

Tebow might be able to contribute in some different ways than a traditional third quarterback, and the Patriots will give him a chance to show what he can do. But for now, the most important thing for him is showing improvement as a quarterback.

Jamie Collins

Jim Rogash/Getty ImagesSecond-round pick Jamie Collins.

Jamie Collins has been used in a number of roles, both in coverage and rushing the passer. He's been subbing for Brandon Spikes, allowing Dont'a Hightower to slide to the middle, putting Collins on the strong side to deal with the tight end.

It looks like Collins could definitely become another significant member of the linebacker rotation, with a specialty for passing downs. If he can bring quality coverage in the middle of the field, he could mark a major improvement for the Patriots defense.

Aaron Dobson

Jim Rogash/Getty ImagesSecond-round pick Aaron Dobson.

The Patriots needed to hit on some wide receivers in the draft and in the first four days of camp, they've had three who have flashed potential. Kenbrell Thompkins, Josh Boyce and Aaron Dobson have all had time with the top offense, and all have had their moments and impressed teammates.

Ryan Mallett

Jim Rogash/Getty ImagesRyan Mallett

It's a big preseason for Ryan Mallett, who will enter the final year of his rookie deal next offseason. If he wants to entice teams to make a trade for him, this summer will be the time to do so. He figures to see less time in the preseason than previous seasons, given Tom Brady is trying to break in some new receivers. Mallet must make the most of his opportunities.

Ryan’s improved every year. This is his third season and we’ve seen a lot of progress from him in this spring and thus far in training camp as well. It looks like he’s very focused, ready to go, his throwing mechanics and techniques are good. His accuracy is good. He reads defenses and coverages. I think he’s continued to make a jump forward in his progression as a football player.

Brandon Spikes

Stew Milne-USA TODAY SportsBrandon Spikes

After an offseason spent training in Florida, Brandon Spikes is back on the field for the Patriots, manning his middle linebacker starting spot in the base defense. In the early days of camp, Spikes has been coming off the field for Jamie Collins to give the Pats a better pass defense, while Dont'a Hightower slides into Spikes' spot in the middle.

The Patriots needed to address the pass coverage from their linebackers, and with Spikes entering a contract year, it appears his chances to prove he's improved his coverage skills will be limited.

Bill Belichick

Winslow Townson-USA TODAY SportsHead coach Bill Belichick.

Bill Belichick is back for his 14th season with the New England Patriots, with a young defense that returns almost completely intact from last season. Belichick's rebuild of the defense began in full force in 2009 and now features a collection of highly drafted players who have accrued multiple seasons together.

The Patriots' dynasty defense of the 2000s peaked after falling short in the late-90s. Belichick's new defense should hit its stride this season.

Vince Wilfork

Wilfork is the key cog for the Patriots defense and should get some help this season with the mountainous Tommy Kelly lined up inside next to him. With offenses less able to focus solely on blocking Wilfork inside, it should free him from double-teams and allow him to make more plays than ever.

Dennard was the star of the second day of Patriots training camp practice, coming away with an interception over Josh Boyce and a pass breakup over Aaron Dobson. Dennard was playing outside and inside on the first team. He was mostly working in the nickel Friday but took extensive snaps in the base defense Saturday.

Stevan Ridley

Jim Rogash/Getty Images

Stevan Ridley had two fumbles in practice on Sunday, picking up where he left off last season. He took penalty laps for both. Ridley has had late-season ball security issues his first two years in the NFL, and the recurrence of the problem early in training camp is a reminder it's an area of his game that must be improved.